In many modern full-duplex audio communication systems, echo cancellers are generally employed to eliminate acoustic feedback introduced in the speaker. By simulating the acoustic echo path, the echo signal may be subtracted from the signal on the return path. The difficulties of acoustic echo cancellation are mainly due to the high computational complexity of the echo canceller and influences which disturb the adaptation of the canceller, such as ambient noise, near end speech, and variations of the acoustic environment. Echoes are particularly difficult to cancel in many modern digital voice communication systems due to the increased latency introduced by packetization and/or compression techniques. For example, in many modern digital audio communication systems when both persons are talking at the same time, it may be difficult for an echo cancellation algorithm to converge fast enough to suppress the echo. Furthermore, in many modern digital audio communication systems when the echo environment changes, the echo cancellation algorithm may fail to converge sometimes causing an even worse echo.
Thus, there are general needs for audio communication devices and methods for reducing echoes in modern digital voice communication systems. There are also general needs for audio communication devices and methods for reducing echoes in modern digital voice communication systems capable of reducing echoes regardless of the acoustic environment.